A stock GSR head is going to flow better than a stock RS/LS/GS head.
The GSR has a higher redline than the RS/LS/GS motor.

Both of these factors combine to make the GSR more efficient than the non-VTEC motors at a fixed boost level.

So if all you plan to do is build a decent streetable setup without going inside the motor.. go with the GSR.

But if you plan on tearing down the motor to build for a high-boost (12 psi+) build..then an non-VTEC Integra will do fine. The money saved by going with a DC4 can go into headwork and cams that will address the inefficiencies of the stock LS head.